Magnetic rail type conveyor unit

ABSTRACT

An overhead magnetic conveyor rail unit which is characterized by a relatively narrow, elongate support frame having rotatable members at opposite ends for supporting a pair of relatively narrow, endless traveling belts on the lower runs of which metal plates are adapted to be held by magnetic force supplied by magnets carried in a series of small inverted, U-shaped housings slidingly mounted for movement longitudinally of the support frame on tensioned cable members extending along opposite sides of the support frame, with belt guide members extending into grooves on opposite sides of the belts, the guide members between the pair of belts constituting magnet pole pieces and the belt guide contacting arrangement being such that friction is reduced when the belts are operating to carry thereon metal sheet members, or the like. In a modified structure the rail unit is formed by mounting on the support frame in the same manner a series of magnet housings having rotatable magnet pole bars with wheel-like end extensions having peripheral rims on which the metal plates are carried.

United States Patent [1 1 Buccicone 1 1 Nov. 12, 1974 1 MAGNETIC RAIL TYPE CONVEYOR UNIT [75] Inventor: Dario Buccicone, Gary, Ind.

[73] Assignee: Bucciconi Engineering Co., Inc.,

Gary, 1nd.

221 Filed: Sept. 4, 1973 211 Appl. No.: 393,780

2 486,733 11/1949 Buccicone t t 198/41 3,297,136 1/1967 Buccicone 198/41 3,782,529 1/1974 Buccicone 198/41 Primary Examiner-Richard A. Schaeher Assistant Examiner.lames M. Slattery Attorney, Agent, or Firm-Guy A. Greenawalt [57] ABSTRACT An overhead magnetic conveyor rail unit which is characterized by a relatively narrow, elongate support frame having rotatable members at opposite ends for supporting a pair of relatively narrow, endless traveling belts on the lower runs of which metal plates are adapted to be held by magnetic force supplied by magnets carried in a series of small inverted. U-shaped housings slidingly mounted for movement longitudinally of the support frame on tensioned cable members extending along opposite sides of the support frame, with belt guide members extending into grooves on opposite sides of the belts, the guide members between the pair of belts constituting magnet pole pieces and the belt guide contacting arrangement being such that friction is reduced when the belts are operating to carry thereon metal sheet members. or the like. In a modified structure the rail unit is formed by mounting on the support frame in the same manner a series of magnet housings having rotatable magnet pole bars with wheel-like end extensions having peripheral rims on which the metal plates are carried.

25 Claims, 14 Drawing Figures MAGNETIC RAIL TYPE CONVEYOR UNIT This invention relates to article conveyors and is more particularly concerned with improvements in overhead conveyors of the type which employ magnetic force for holding metal sheets or similar articles wherein relatively narrow belts are employed which are substantially less in width than the width at the bottom of the conveyor'rail and which are arranged in spaced grooves or guide recesses on thebottom forming surface of a belt guiding plate which is secured at thebottom of the conveyor rail. Due to the belt weight and the unsupported length it has been customary to curve or bow the bottomiface of the conveyor rail in order to accommodate a portion of the belt sag and reduce the amount of tension required to'keep the beltseated in the guide grooves. With the relatively long and heavy belts employed in handling sheets which are large and heavy it has not been practical to apply a sufficient amount of tensionto the belt to keep it traveling in a level plane. While thistype of rail conveyor has been used extensively'for handling flat metal sheets which will bend sufficiently to followthe bowed contour of the bottom face of the' conveyor unit, some metal sheets, because oftheir thickness or other characteristics,have .too'great resistance tobowing to permit them to 'be handled satisfactorily with this type conveyor unit. Various modifications have beentried in an effort to adapt the multiple belt-type conveyor for the handling of sheets having ahigh resistance to longitudinal bowing but with little success. Wide belt arrangements have been resortedto for handling sheets of this character but they have generallynot been successful because of the inability'to overcome a tendency to sag excessively due to their weight, particularly, when the conveyors are of a substantial length, and because of inadequate provision for accommodating irregularities inthe sheet surface dueto warping orthe like, with the result that they cannot be held against dropping away from the surface of the wide belt except through the use of very high strength magnets which greatly in creases operating costs. One form of wide belt conveyor which provides a flat surface bottom run is shown in my U.S. Pat. No. 3,229,805, grantedJan. 18, 1966.

"While this form of conveyor provides a flat belt surface for engaging the metal sheets, the belt arrangement lacks flexibility and satisfactory magnetic pull cannot be had without too large magnets. Also, the thickness of the belt is reduced with the result that the belts life is greatly lessened as compared with the narrow belts which have substantially greater thickness.

One form of narrow belt conveyor which has been designed to handling sheets having bowing or other surface deforming irregularities is illustrated in my U.S. Pat. No. 3,144,927, dated Aug. 18, 1964. Thisconveyor has been successfully employed in the handling of most sheet materials but it has been found to have limitations, particularly in the handling of relatively large thick sheets where the weight of the sheet is an important factor. Another form of conveyor which has a certain amount of flexibility in the lower belt run is shown in my U.S. Pat. No. 3,297,136, granted Jan. 10, 1967. This conveyor employs a wide belt which has the disadvantages referred to. Consequently, there appears to be a need for further improvements in overhead conveyors of this general type which will handle in a more satisfactory manner metal plates or similar material having bowing or other surface deforming irregularities, and, therefore, it is a general object of the present invention to provide an improved conveyor rail unit of the type having abottom plate carrying surface which will conform in some degree to the contour of the ma terial being held for advance thereon by magnetic force.

A more specific object of the invention is to provide a rail-type magnetic conveyor for transporting and handling metal sheets which are characterized by a high resistance to bending in either direction and which may present to the sheet contacting surface-of the conveyor belt a sheet surface having waves or other irregularities therein, which conveyor has a work surface with sufficient flexibility to conform generally to irregularities in the surface of a sheet being carried thereon.

It is another object of the invention to provide a conveyor for metal sheets wherein an endless traveling belt is supported at opposite ends of an elongate frame and a plurality of magnets are disposed in longitudinally spaced relation along the frame above the lower run of the belt which magnets are operated to hold the sheets against the bottom surface of the belt by magnetic force with the magnets being carried on downwardly opening, generally U-shaped frames slidably mounted on longitudinally extending cable members which are supported so as to provide a normally flat bottom run of the belt on the surface of which the sheet canbe carried in a generally flat condition with the belt having a degree of flexibility so as to enable it to conform generally to irregularities in the surface of the sheet.

It is a further object of the invention to provide a conveyor for metal sheets wherein an endless traveling belt is supported at opposite ends of an elongate frame and a plurality of magnets are disposed in longitudinally spaced relationalong the frame and above the lower run of the belt which magnets are operated to hold the sheets against the bottom surface of the belt by magnetic force, with the magnets being carried on downwardly opening frames which are slidably mounted for movement in a longitudinal direction on a pair of longitudinally extending cable forming members thereby permitting the magnet carrying frames to move relative to each other and to enable the belts to conform at least inpart to irregularities in the belt surfaces of the sheets asthey advance along the bottom run thereof.

It is a still further object of the invention to provide a conveyor unit capable of handling relatively heavy metal sheets which have a high resistance to bending so that the sheets'may be carried while they remain in fixed planes wherein the conveyor is characterized by an elongate supporting frame having endless traveling belts mounted on 'end supports which are longitudinally spaced with a plurality of electromagnet assemblies and belt guide units spaced longitudinally above the lower runs of the belts and supported on small cross frames which are connected to each other in sliding relation on longitudinally extending support cables, enabling the individual magnet and belt guide assemblies to rise and fall according to the contour of the surface of the sheet as it is advanced beneath the conveyor, thereby permitting apredetermined degree of conformity to surface irregularities of the sheets.

Still another object of the invention is to provide a conveyor unit of the type described for handling metal sheets or similar material, with the unit having a special belt and belt guiding or supporting construction which enables frictional contact between the belt and the guides to be relieved during material conveyance.

A further object of the invention is to provide a con veyor unit of the type described wherein the electromagnets are supported individually on downwardly opening housing members slidably mounted on spaced, longitudinally extending cables so that the magnet units are enabled to move relative to each other which permits the lower run of the belt to conform at least in part to irregularities in the belt engaging surface of the sheets as they are advanced thereon.

Another object of the invention is to provide an improved conveyor unit of the type described wherein the magnets and belt guiding means are mounted so as to provide a degree of flexibility in the article carrying bottom belt run, with the support means for the magnet and the belt guiding means being readily adapted to provide either a bowed bottom work surface or a substantially flat bottom work surface, as desired.

A still further object of the invention is to provide an improved overhead conveyor rail unit for handling metal sheet or plate-like material wherein the unit has a supporting frame and a series of magnet housings slidably mounted on cable suspending means carried by the supporting frame with the magnet housings each having a magnet coin therein and a rotatably mounted magnet core, or pole bar member, with end extensions in the form of wheels on the peripheral rims of which the material is held by magnetic force for advance along the bottom of the unit.

Theseand other objects and advantages of the invention will be apparent from a consideration of the conveyor structure which is shown by way of illustration in the accompanying drawings wherein:

FIG. 1 is a side elevational view, with portions broken away, of a sheet piler employing a magnetic rail conveyor unit which incorporates therein the principal features of the present invention;

FIG. 2 is a partial plan view, with portions broken away or omitted, of the piler apparatus of FIG. 1;

FIG. 3 is a side elevational view, to an enlarged scale, of the entrance end of one of the conveyor rail units;

FIG. 4 is a longitudinal section taken on the line 4-4 of FIG. 3; 8

FIG. 5 is a side elevational view, to an enlarged scale, of a portion of the rail unit showing particularly the exit end thereof;

FIG. 6 is a longitudinal section on the line 6-6 of FIG. 5;

FIG. 7 is a cross section-taken on the line 7-7 of FIG. 1, to an enlarged scale;

FIG. 8 is a view, partially in elevation and partially in longitudinal section, to a greatly enlarged scale, showing details of the magnetic assemblies;

FIG. 9 is a cross section taken on the line 9-9 of FIG. 8;

FIG. 10 is a cross section taken on the line l0l0 of FIG. 8;

FIG. 11 is a partial cross sectional view taken on the same plane as FIG. 9 but showing a modified belt structure;

FIG. 12 is a partial cross sectional view taken on the same plane as FIG. 10 but showing the modified belt structure;

FIG. 13 is a side elevational view showing a modified form of rail structure; and

FIG. 14 is a cross sectional view taken on the line 14-14 of FIG. 13, to an enlarged scale.

Referring to FIGS. 1 and 2, there is illustrated a piler assembly comprising a pair of rail-like conveyor units 10 mounted in parallel, side-by-side relation on upright end supports 11 and 12. The assemblies shown embody the main elements of the sheet piler with suitable means (not shown) for supporting a pile of sheets between the end frames ll and 12 and suitable end stop and back stop devices (not shown). As infeed conveyor 13 and associated drive means 14 is mounted at the entrance end of the piler and drive means 15 for the conveyor units 10 is provided at the opposite end thereof.

Each of the conveyor rail units 10 comprises an elongate support frame 20 (FIGS. 1 and 7) with pulley housings 21 and 22 mounted at the entrance and exit ends thereof, respectively. Belt supporting idler and drive pulleys or rollers 23 and 24 are mounted on transversely extending shafts 25 and 26 in the housings 21 and 22 for supporting at opposite ends of the frame a pair of traveling belts 28 with predetermined transverse spacing. The belts 28 are of identical construction and have a combined width sufficient for the bottom faces of the bottom run to extend across the major portion of the sheet engaging bottom face of the unit.

Each rail conveyor unit 10 comprises elongate side plates 30 and 30' (FIG. 7) which are vertically disposed and in laterally spaced, parallel relation. these side plates 30 and 30' are connected by cross members at their ends and intermediate the same by a bottom plate 31. A cover member 32 is provided for the top of the conveyor frame.

A series of magnet supporting and belt guiding assemblies 34 (FIGS. 2, 7 and 9) are mounted beneath the bottom plate 31 of the frame 20 and connected in articulated relation by stringing the same on parallel runs 36, 36' of a cable suspension 38 which will be hereinafter described.

Each of the magnet supporting and belt guiding assemblies 34 comprises a downwardly opening, generally U-shaped housing or frame 40 with side or leg forming plates 41 and 41' having attached to the outer faces thereof pairs of bearing blocks 42 and 42', with each pair thereof having aligned cable receiving bores 43 and 43' in which longitudinal cable runs 36 and 36 extend in parallel relation. The bearing blocks, 42, 42' may be split with a bolt connection, as illustrated particularly in FIG. 9, for ease in assembly and replacement of the units. Within each housing 40 there is mounted an electromagnet coil 44 and a magnet core 45 with the core 45 depending from the housing top wall 46 and secured thereto by a connecting bolt 47. A washer 48 is held on the lower end of the core 45 by a snap ring 50 and retains the coil 44 on the core 45. At its lower end the core 45 has a section 51 of reduced transverse dimension and on its bottom end there is attached an elongate pole bar 52 by means of the bolt 53 with the pole bar extending longitudinally of the conveyor unit, as shown in FIG. 8, andhaving the cross section shown in FIG. 9. The cross sectional configuration of the pole bar 52 provides side edges or side margins with the top and bottom marginal surface portions 54, 54' and 55, 55 extending in converging relation to an outer marginal curved portion 56, 56' and each side of the pole bar serves as a guide rail for one of the belt members 28. The belt members 28 which are of rubber, or similar material, are grooved in their opposite side edges with the groove configuration 57, 57 being the same on both sides and for both belts 28. The outermost or outboard face of each belt 28 is covered with a member 58, preferably a synthetic rubber, such as, polychloroprene (Neoprene) of substantial thickness providing, as shown in FIG. 9, on the bottom run thereof a bottom surface having a width which is somewhatgreater than the width of the top or inboard surface 60 of the belt. The side edge grooves 57, 57 each have top and bottom surface portions 61, 61 and 62, 62' which converge to a curved inner surface portion 63, 63' and which extend generally parallel to the ta pered surfaces 54, 54' and 55, 55' of the side margins of pole bar 52 with which they co-operate in guiding the belts. Guide rails 64 and 64 which have the same cross sectional configuration as the side marginal or edge portions of the pole bar 52 are mounted on the bottom ends of the housing side plates 41 and 41' as shown in FIGS. 9 and 10. Side guide rail and belt engagement is the same as the pole bar and belt engagement with the top portions 61, 61 of the belt grooves 57, 57 engaging the top surface portions 54, 54' of the pole bar 52 and the top surface portions 65, 65' of the side guide rail members 64,64 when the belts 28 are not carrying material. In this condition the lower surface portions 62, 62 of the belt members 28 are spaced from the bottom surface portions 55, 55 of the pole bar 52 and the bottom surface portions 66, 66 of the side guide rail members 64, 64'. The outermost side edges of the belts 28 extend beneath the bottom edges of the housing side plates 41 and 41 and the latter are cut away on the outside at 67 and 67 to reduce the possibility of contact'of the sheet material which is being'carried with the edges of the housing plates 41 and 41'. In alike manner, the lower or'outermost portions of the opposed inner edges of the belts 28 extend somewhat beneath the lower face 68 of the pole bar 52 leaving space for free passage of the magnetic force. The axial dimension of the bottom portion 51 of the core 45 is sufficient to eliminate any possibility of con-' tract of the top surfaces 60 of the belts 28 contacting the main body of the. core 45 when the belts 28 are lifted off the pole bar 52 and the side guide rails 64, 64' by pressure of the material being carried which results from the pull exerted by the magnets. The arrangement provides minimum contact between the belts and the guide rails when the belts 28 are operating without carrying material and are drawn by the sag or weight of the belts into engagement with the top surface portions 54, 54 of the pole bar 52 and the top portions 65, 65 of theside guide rails 64, 64'.

Each of the magnet supporting assemblies 34 has mounted thereona roller assembly 70 (FIGS. 8 and for support of the belts when they are pulled upwardly by pressure of the material being carried. Each roller assembly 70 comprises a pair of roller members 71, 71

mounted on a cross shaft 72 which is supported on a center bracket 73 (FIG. 10). The bracket 73 is attached in depending or suspended relation to the housing top plate 46. The housing side plates 41 and 41 have curved edges 75, 75' (FIG. 8) which are adapted to abut the corresponding edges of the side plates of adjacent units. Each roll assembly 701 is positioned so that the rollers 71, 71 serve to support the belts 28 when they are lifted due to the attraction of the magnets exerted upon the plates or other material being carried on the belts 28 with the result that when the belts 28 are operating to carry material they are running substantially free of frictional contact with the guide forming pole bars 52 and side guide rails 64 and 64'.

The cable or rope assembly 38 (FIGS. 3 to 6) is supported at one end of the conveyor frame 20 on a pair of laterally spaced pulley members 80, which are mounted on shafts 81, 81' upstanding from a cross frame 82 on the main frame 20. At the other end of the frame 20, the cable 38 is connected to a spring tension device 83. The cable runs 36, 36' pass around pulleys 84, 84' which are carried on a pair of stub shafte 85. Shafts 85 are journaled in a suitable bearing member 86. The ends of the cable runs 36, 36' have eye socket members 87, 87' which are connected by pins 88, 88' to connector blocks 90, 91). The connector blocks 90, 90' have headed pins 91, 91 extending into a housing 92 of generally rectangular shape and cross section. The pins 91, 91' extend in slidable relation through apertures 93, 93' in the bottom or end wall 94 of the housing 92 and compression springs 95, 95 are carried on the pins 91, 91' between the pin heads and the housing wall 94. The opposite wall 96 of the housing has a threaded pin 97 extending therefrom which is slidable in an aperture 98 in a cross bar member 99 and which has a nut 100 thereon for bearing against the top face of the-cross member 98. The cable members 36, 36' may be readily released by removal of pins 88, 88. The housing 92 has open sides and may be readily removed for servicing when released from the cross member 98 by removal of the nut 101).

When the conveyor unit has relativelylong length, some of the cable carried magnet units 34 may be resiliently and adjustably suspended from the frame 20 by the suspension means 102 as shown in FIG. 7.The top plate 46 on the magnet unit is provided with an upstanding bolt or threaded pin 104 which extends through an opening 105 in the frame bottom plate 31 and carries a compression spring 106 which extends between a curved bottom washer 107 and an end nut 98 and washer 108. The suspended units 34 may be spaced along the conveyor as required to support the cable carried units in a generally horizontal plane. the belts 28 may be allowed to sag and provide a curved bottom on the rail unit by omitting the suspension and allowing the units 34 to be supported by the cable runs 36, 36 along. The belts 28 will be given a degree of tension by means of a spring tensioning device 110(FIGS. I and 3) for example as described in my US. Pat. No. 3,150,764, granted Sept. 29, 1964. Side guard plates 111, 111' may be provided on the frame 20 which extend down over the cable runs 36, 36 for protecting the apparatus.

A modified form of the belt and the roller supports therefor is illustrated in FIGS. 11 and 12 which is designed to facilitate mounting and removal or replacement of the belt. In the form illustrated, the belt 112 is provided, in its back face 1 14 and along its longitudinal center line, with a relatively deep groove 115 which is generally V-shaped in cross section with the thickness of the belt at the apex 116 substantially less than at the maximum thickness areas. The cross section of the belt 112 is otherwise the same as the belts 28 with side edge grooves 117, 117 for co-operation with core extensions 118 and side rails 120 as shown in the form of the belts illustrated in FIGS. 1 to 10. The belt 112 is supported on rollers 121 which have a circumferential, radially projecting rib 122 with a cross sectional configuration complementary to the cross sectional configuration of the belt groove 115 so as to track the belt. The grooved configuration of the belt 112 facilitates removal and replacement of the belt 112. The belt groove 115 is such that the belt may be collapsed as illustrated in phantom line in FIG. 11 to permit release of the belt 112 from engagement with the core extensions 118 and side rail members 120 when the belt tension is reduced sufficiently to allow the belt to drop free of the guide members. A reverse operation is followed in replacing the belt to its operative position.

Referring to FIGS. 13 and 14, a cable suspension system may be employed in a rail unit 125 having magnet assemblies 126 of the roller or wheel type, such as, disclosed in my U.S. Pat. No. 2,947,429, granted Aug. 2, 1960. In this form of rail unit a plurality of magnet assemblies 126 are mounted on a suspension cable 127 which may be constructed in a manner similar to the cable suspension shown in FIGS. 1 to 10. The cable 127 includes longitudinally extending runs 128, 128' on which the magnet assemblies 126 are mounted for sliding movement longitudinally of rail unit 125.

Each magnet assembly 126 comprises a magnet housing 130 enclosing a magnet coil 131 through which there extends a rotatably mounted pole piece or magnet'core member 132 with its axis extending transversely of the housing 130 and the elongate frame 133 which constitutes the supporting structure for the rail unit 125. The core member 132 is supported at oppositeends in bearing members 134, 134' inthe housing side walls 135, 135 and has its ends extended beyond the outer faces of the housing side walls 135, 135' so as to mount thereon wheel-like core extensions 136, 136' of identical construction. Each of the core extensions 136, 136' comprises a wheel plate 137, with a rim member 138 on the periphery which has a cover 140 of rubber or other cushioning material which will not scratch the surface of the sheets when engaged therewith.

Each magnet housing 130 is mounted on the cable runs 128, 128' by means of a pair of frame members 141 which are attached to the top wall 142 of the housing 130 and have opposite end portions extending downwardly and outwardly along the sides thereof and outwardly of the wheel assemblies 136, 136' with cable receiving bearing members 143, 143 on the ends thereof which are in paired, longitudinally spaced and longitudinally aligned relation on opposite sides of the assemblies 126. The suspension cable 127 may be mounted at opposite ends of the rail frame 133 in the same manner as the cable 38 in the conveyor unit of FIGS. 1 to 10, or in a similar manner, with a tension adjusting apparatus indicated at 144. Also, any desired number of the magnet units 126 may be resiliently suspended from the conveyor frame 133 by a suspension means 145 of the same character as the suspension means 102 which is shown in FIG. 7. Also, fixed rolls may be employed at each end of the unit as indicated at 146 and 147 on FIG. 13.

I claim:

l. A conveyor for metal sheets which comprises an elongate frame having an endless traveling belt member supported on rotatable members mounted at opposite ends of said frame, a plurality of longitudinally spaced magnet assemblies mounted for vertical movement on said frame above the lower run of said belt member, said magnet assemblies including magnets which are operable to exert a magnetic force on a sheet and to hold the same in engagement with the lower surface of said belt member for travel with said belt member, and means extending lengthwise of said frame and connected to said magnet assemblies for suspending said magnet assemblies on said frame, which means is in the form of a cable having a degree of flexibility so as to permit limited movement of said magnet assemblies relative to each other.

2. A conveyor as set forth in claim 1 wherein said means for suspending said magnet assemblies comprises an endless cable member anchored at one end of said frame and carried at the other end of said frame on a pair of laterally spaced pulleys, said cable member having portions extending along opposite sides of said frame with said magnet assemblies slidably connected thereto on opposite sides of said assemblies.

3. A conveyor as set forth in claim 1 wherein said means for suspending said magnet assemblies comprises cable forming members extending along opposite sides of said frame and wherein said magnet assemblies are slidably connected to said cable forming members.

4. A conveyor as set forth in claim 1 wherein said means for suspending said magnet assemblies comprises an endless cable member having a degree of flexibility, means at one end of said frame for mounting said cable member so that it is free to move in an axial direction, said cable member having portions extending along opposite sides of said frame and means at the opposite end of said frame for anchoring the free ends of said cable portions.

5. A conveyor as set forth in claim 4 wherein said cable anchoring means includes a tensioning device.

6. A conveyor as set forth in claim 1 wherein said means for suspending said magnet assemblies comprises at least one cable forming member extending lengthwise of said frame on which said magnet assemblies are slidably mounted wherein said magnet assemblies have associated belt supporting members on which the top surface of said belt rides when held against the same by pressure of a sheet lifted by force of the magnets.

7. A conveyor as set forth in claim 6 wherein said belt supporting members are rotatably mounted belt supporting rollers.

8. A conveyor as set forth in claim 1 wherein said magnet assemblies comprise belt edge engaging guide members.

9. A conveyor as set forth in claim 1 wherein said magnet assemblies have belt edge guiding members and said belt member has edge grooves into which said edge guiding members extend.

10. A conveyor as set forth in claim 9 wherein said belt member has a relatively deep groove in its inboard face which has a cross sectional configuration enabling the belt member to be folded so as to reduce its width sufficiently to permit it to be removed from said edge guiding members in a vertical direction.

11. A conveyor as set forth in claim 1 wherein said belt member has substantial thickness with an inwardly extending groove in each side edge and wherein said magnet assemblies each have a core member and belt edge guiding members, one of which constitutes an end extension on said magnet core member.

12. A conveyor as set forth in claim 1 wherein said traveling belt member has substantial thickness and inwa'rdly extending grooves of predetermined cross sectional configuration in the opposite side edges and wherein said magnet assemblies have spaced guide rail members positioned to extend into said belt grooves which guide rail members have a portion with a cross sectional configuration corresponding substantially to the cross sectional configuration of the side edge grooves in said belt member and said guide rail portions are dimensioned so that they extend into said belt edge grooves and normally support said belt when a sheet is not in engagement with said beltwhile permitting said belt to be raised to a level to travel out of engagement with said guide rail memberswhen a sheet is held in engagement with said belt by magnetic force so as to lift said belt.

13. A conveyoras set forth in claim 12 wherein said magnet assemblies have associated roller members positioned to limit the level to which the bottom run of said belt member may be lifted so as to hold said belt member in a path which frees it of engagement with said guide rail members. a

'14. A conveyor for metal sheets or the like comprising an elongate frame, a plurality of magnet assemblies disposed in longitudinally spaced relation on said frame, means for supporting said magnet assemblies in suspended relation on said frame which is in the form of one or more lengths of a cable'member having a degree of flexibility and extending longitudinally of said frame, means mounting each of said magnet assemblies for limited vertical movement, means for supporting metali'sheets for travel ina path along the bottom of saidmagnet assemblies, and said magnet assemblies including magnets positioned to exert an upward magnetic force on themetalsheets so as to hold saidsheets against said sheet supporting means and enable said sheets to be carried along the bottom of said conveyor.

15. A conveyor as set forth in claim 14 wherein certain of said magnet assemblies comprise a housing with a magnet coil mounted therein, and a core member mounted in said coil for rotation on an axis extending transversely of said conveyor, said core member having one or more end extensions each of which is in the form of a roller with the periphery thereof arranged so as to be engaged by the top surface of a sheet and form said sheet supporting means. i

16. A conveyor as set forth in claim 14 wherein said sheet supporting means is in the form of a pair of relatively narrow, flexible, endless traveling belt members having substantial thickness which are carried on rotatable end members spaced longitudinally on said frame so that the lower runs travel along the bottom of said magnet assemblies, said belt members being spaced laterally to accommodate magnet pole bars disposed in depending relation between the inner edges of the lower runs thereof so as to providemagnetic force sufconstitutes aligned ficient to hold the sheets against the bottom faces of the belts are grooved at their side edges and said magnet assemblies include belt guide rails disposed to extend into the grooves in the belts.

18. A conveyor as set forth in claim 16 wherein said belts have inwardly extending grooves in opposite side edges and said magnet assemblies include guide rail members extending longitudinally of the conveyor frame which project into the belt grooves, one of which bottom end portions of the magnet pole bars.

19. A conveyor as set forth in claim 18 wherein said guide rail members have a cross sectional configuration corresponding to the cross sectional configuration of the belt grooves and a lesser vertical dimension so that in no-load position the belts ride on the guide rail members while in the loaded position the belts are elevated sufficiently to relieve the frictional contact of the belts with the guide members.

20. A conveyor as set forth in claim 19 wherein said magnet assemblies have associated support members engageable by the top faces of the belts which limit the distance the belts may be raised relative to the guide rail members when upward magnetic force is applied to the metal sheets carried on the belt bottom faces.

21. A conveyor as set forth'in claim 14 wherein said sheet supporting means includes a relatively thick flat belt member supported for travel beneath said magnet assemblies, said belt member having grooves of substantial depth extending inwardly of the side edge faces thereof for receiving guide rail forming members on said magnet assemblies when the belt member is in normal operative condition and the inboard face of said belt member having one or more groove formations therein which extend longitudinally of said belt member andwhich enable said belt member to be collapsed on its longitudinal axis so as to disengage it from said guide rail forming members.

22. A conveyor as set forth in claim 14 wherein said sheet supporting means includes an endless traveling belt and wherein said magnet assemblies have associ ated belt supporting rollers against which the inboard magnet coil mounted therein and a pole bar extending transversely of said frame and rotatably mounted in said frame with wheel-like end members which constitute said means for supporting the sheets for travel along the bottom of said magnet assemblies.

24. A conveyor for metal sheets which comprises an elongage frame having an endless traveling belt adjustably mounted on pulleys at opposite ends of said frame, a plurality of longitudinally spaced magnet assemblies mounted for vertical movement in said frame above the lower run of said belt, said magnet assemblies including magnets which are operable to exert an upward magnetic force on a sheet and to hold the same. against the bottom surface of said belt run, means extending lengthwise of said frame and connected to said magnet assemblies for suspending said magnet assemblies in said frame which means is in the form of acable having a degree of flexibility, and said magnet assemblies having abutting portions which permit limited tilting movement of said magnet assemblies relative to each other.

25. In a sheet handling conveyor of the overhead type which employs a series of magnet assemblies and an endless traveling belt member mounted on an elongate frame with the lower run traveling in a generally horizontal path beneath the magnet assemblies which are operative to hold the sheets on the bottom face of said lower belt run by magnetic force, an endless belt structure of rubber or rubber-like material having a relatively narrow width and substantial thickness which belt structure includes relatively deep grooves in the opposite side edges for receiving guide rail members so as to guide the same for travel in a predetermined path,

is adapted to be received in the groove.

.UNITED STATES PATEN'L OFF ICE (s/ng) CERTIFICATE I OF CORRECTION Patent No. 3,847,269 l Dated November 12, 1974 Invcntofls) Dario Buccicone It is certified that arrow: appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 35, "coin" should be coil Column 4, line 20 "As" should be An Column 4, line 39, 'f these" should be ---Ifhes e I Column 5, l'ins 51 and 52, "contract" should be contact Column 6, line '22-, "shafte" should begs-5118115135;

Column 5, liloe 53 "the" should be The Signed and sald this 11th day of February 1975 (SEAL) Attest: j

V C. MARSHALL DANN l RUTH C. MASON Commissioner of Patents Att sting Officer and Trademarks 

1. A conveyor for metal sheets which comprises an elongate frame having an endless traveling belt member supported on rotatable members mounted at opposite ends of said frame, a plurality of longitudinally spaced magnet assemblies mounted for vertical movement on said frame above the lower run of said belt member, said magnet assemblies including magnets which are operable to exert a magnetic force on a sheet and to hold the same in engagement with the lower surface of said belt member for travel with said belt member, and means extending lengthwise of said frame and connected to said magnet assemblies for suspending said magnet assemblies on said frame, which means is in the form of a cable having a degree of flexibility so as to permit limited movement of said magnet assemblies relative to each other.
 2. A conveyor as set forth in claim 1 wherein said means for suspending said magnet assemblies comprises an endless cable member anchored at one end of said frame and carried at the other end of said frame on a pair of laterally spaced pulleys, said cable member having portions extending along opposite sides of said frame with said magnet assemblies slidably connected thereto on opposite sides of said assemblies.
 3. A conveyor as set forth in claim 1 wherein said means for suspending said magnet assemblies comprises cable forming members extending along opposite sides of said frame and wherein said magnet assemblies are slidably connected To said cable forming members.
 4. A conveyor as set forth in claim 1 wherein said means for suspending said magnet assemblies comprises an endless cable member having a degree of flexibility, means at one end of said frame for mounting said cable member so that it is free to move in an axial direction, said cable member having portions extending along opposite sides of said frame and means at the opposite end of said frame for anchoring the free ends of said cable portions.
 5. A conveyor as set forth in claim 4 wherein said cable anchoring means includes a tensioning device.
 6. A conveyor as set forth in claim 1 wherein said means for suspending said magnet assemblies comprises at least one cable forming member extending lengthwise of said frame on which said magnet assemblies are slidably mounted wherein said magnet assemblies have associated belt supporting members on which the top surface of said belt rides when held against the same by pressure of a sheet lifted by force of the magnets.
 7. A conveyor as set forth in claim 6 wherein said belt supporting members are rotatably mounted belt supporting rollers.
 8. A conveyor as set forth in claim 1 wherein said magnet assemblies comprise belt edge engaging guide members.
 9. A conveyor as set forth in claim 1 wherein said magnet assemblies have belt edge guiding members and said belt member has edge grooves into which said edge guiding members extend.
 10. A conveyor as set forth in claim 9 wherein said belt member has a relatively deep groove in its inboard face which has a cross sectional configuration enabling the belt member to be folded so as to reduce its width sufficiently to permit it to be removed from said edge guiding members in a vertical direction.
 11. A conveyor as set forth in claim 1 wherein said belt member has substantial thickness with an inwardly extending groove in each side edge and wherein said magnet assemblies each have a core member and belt edge guiding members, one of which constitutes an end extension on said magnet core member.
 12. A conveyor as set forth in claim 1 wherein said traveling belt member has substantial thickness and inwardly extending grooves of predetermined cross sectional configuration in the opposite side edges and wherein said magnet assemblies have spaced guide rail members positioned to extend into said belt grooves which guide rail members have a portion with a cross sectional configuration corresponding substantially to the cross sectional configuration of the side edge grooves in said belt member and said guide rail portions are dimensioned so that they extend into said belt edge grooves and normally support said belt when a sheet is not in engagement with said belt while permitting said belt to be raised to a level to travel out of engagement with said guide rail members when a sheet is held in engagement with said belt by magnetic force so as to lift said belt.
 13. A conveyor as set forth in claim 12 wherein said magnet assemblies have associated roller members positioned to limit the level to which the bottom run of said belt member may be lifted so as to hold said belt member in a path which frees it of engagement with said guide rail members.
 14. A conveyor for metal sheets or the like comprising an elongate frame, a plurality of magnet assemblies disposed in longitudinally spaced relation on said frame, means for supporting said magnet assemblies in suspended relation on said frame which is in the form of one or more lengths of a cable member having a degree of flexibility and extending longitudinally of said frame, means mounting each of said magnet assemblies for limited vertical movement, means for supporting metal sheets for travel in a path along the bottom of said magnet assemblies, and said magnet assemblies including magnets positioned to exert an upward magnetic force on the metal sheets so as to hold said sheets against said sheet supporting means and enable said sheets to be carried along the bottom of said conveyor. Pg,27
 15. A conveyor as set forth in claim 14 wherein certain of said magnet assemblies comprise a housing with a magnet coil mounted therein, and a core member mounted in said coil for rotation on an axis extending transversely of said conveyor, said core member having one or more end extensions each of which is in the form of a roller with the periphery thereof arranged so as to be engaged by the top surface of a sheet and form said sheet supporting means.
 16. A conveyor as set forth in claim 14 wherein said sheet supporting means is in the form of a pair of relatively narrow, flexible, endless traveling belt members having substantial thickness which are carried on rotatable end members spaced longitudinally on said frame so that the lower runs travel along the bottom of said magnet assemblies, said belt members being spaced laterally to accommodate magnet pole bars disposed in depending relation between the inner edges of the lower runs thereof so as to provide magnetic force sufficient to hold the sheets against the bottom faces of the lower belt runs.
 17. A conveyor as set forth in claim 16 wherein said belts are grooved at their side edges and said magnet assemblies include belt guide rails disposed to extend into the grooves in the belts.
 18. A conveyor as set forth in claim 16 wherein said belts have inwardly extending grooves in opposite side edges and said magnet assemblies include guide rail members extending longitudinally of the conveyor frame which project into the belt grooves, one of which constitutes aligned bottom end portions of the magnet pole bars.
 19. A conveyor as set forth in claim 18 wherein said guide rail members have a cross sectional configuration corresponding to the cross sectional configuration of the belt grooves and a lesser vertical dimension so that in no-load position the belts ride on the guide rail members while in the loaded position the belts are elevated sufficiently to relieve the frictional contact of the belts with the guide members.
 20. A conveyor as set forth in claim 19 wherein said magnet assemblies have associated support members engageable by the top faces of the belts which limit the distance the belts may be raised relative to the guide rail members when upward magnetic force is applied to the metal sheets carried on the belt bottom faces.
 21. A conveyor as set forth in claim 14 wherein said sheet supporting means includes a relatively thick flat belt member supported for travel beneath said magnet assemblies, said belt member having grooves of substantial depth extending inwardly of the side edge faces thereof for receiving guide rail forming members on said magnet assemblies when the belt member is in normal operative condition and the inboard face of said belt member having one or more groove formations therein which extend longitudinally of said belt member and which enable said belt member to be collapsed on its longitudinal axis so as to disengage it from said guide rail forming members.
 22. A conveyor as set forth in claim 14 wherein said sheet supporting means includes an endless traveling belt and wherein said magnet assemblies have associated belt supporting rollers against which the inboard face of the belt is drawn by said magnets.
 23. A conveyor as set forth in claim 14 wherein said magnet assemblies each comprise a frame having a magnet coil mounted therein and a pole bar extending transversely of said frame and rotatably mounted in said frame with wheel-like end members which constitute said means for supporting the sheets for travel along the bottom of said magnet assemblies.
 24. A conveyor for metal sheets which comprises an elongage frame having an endless traveling belt adjustably mounted on pulleys at opposite ends of said frame, a plurality of longitudinally spaced magnet assemblies mounted for vertical movement in said frame above the lower run of said belt, said magnet assemblies including magnets which are operable to exert an upward magnetic force on a sheet anD to hold the same against the bottom surface of said belt run, means extending lengthwise of said frame and connected to said magnet assemblies for suspending said magnet assemblies in said frame which means is in the form of a cable having a degree of flexibility, and said magnet assemblies having abutting portions which permit limited tilting movement of said magnet assemblies relative to each other.
 25. In a sheet handling conveyor of the overhead type which employs a series of magnet assemblies and an endless traveling belt member mounted on an elongate frame with the lower run traveling in a generally horizontal path beneath the magnet assemblies which are operative to hold the sheets on the bottom face of said lower belt run by magnetic force, an endless belt structure of rubber or rubber-like material having a relatively narrow width and substantial thickness which belt structure includes relatively deep grooves in the opposite side edges for receiving guide rail members so as to guide the same for travel in a predetermined path, each of said grooves being formed with a cross sectional configuration which provides inwardly converging top and bottom surfaces terminating at an area spaced inwardly of the side edges, said groove defining top and bottom surfaces being spaced apart a substantial distance at the groove entrance so as to receive a guide rail forming member having a like cross sectional configuration providing top and bottom bearing surfaces and said groove defining surfaces being spaced apart a distance greater than the corresponding spacing of the bearing surfaces of the guide rail member which is adapted to be received in the groove. 